[RADIOLAB FOR KIDS INTRO]

LULU MILLER: Here I am in the heart of New York City. And I'm just like, you know, in the middle of a city park. There's a fountain. There's a coffee shop. There's some people doing tai chi, a guy walking a dog. But somebody in this park has been to the moon, and we are going to go try to find it.

LULU: Hey, Lulu Miller here with some breaking moon tree news! We have just received the coordinates of a moon tree that was recently, secretly, planted in the middle of New York City! That's right, a tree planted from a seed that went to the moon is quietly taking root in the heart of the Big Apple. And recently, producer bud Ana and I went to go find it.

LULU: And I'm so excited. And I don't even know what species it is, so I'm just looking around and I'm like, "Ooh, here's a little sapling with kind of heart-shaped leaves. Are you a moon tree?" "Ooh, here's a cool one with kind of like moody, whitish-green leaves. Are you a moon tree?"

LULU: And suddenly, we spotted it, off in a grassy spot on the north side of the park, surrounded by a fence.

ANA GONZÁLEZ: What does it look like from afar?

LULU: Okay, from afar it looks like a very tiny tree. It is—although it's taller than this wom—it's, like, about the height of a human adult. Its leaves are green. Are we a maple? What ...

STEPHANIE LUCAS: So this is a sweetgum.

LULU: A sweetgum!

STEPHANIE LUCAS: American sweetgum.

LULU: That's the voice of Stephanie Lucas, who's kind of the mom of the moon tree.

STEPHANIE LUCAS: I'm the director of horticulture and park operations at Madison Square Park Conservancy.

LULU: Madison Square Park, by the way, is not a garden near Madison Square Garden, it's the garden near the Flatiron Building, which Stephanie informed me is not a garden.

STEPHANIE LUCAS: We're an arboretum. We're a tree museum.

LULU: A museum of trees. They have over 300 trees: trees that bloom with pink flowers or yellow flowers, trees that grow delicious red berries. An umbrella tree from Japan, an oak tree from a president's garden.

STEPHANIE LUCAS: Right behind us we have an English elm.

LULU: She points to a massive tree that's around 200 years old.

STEPHANIE LUCAS: Which is one of the great trees of New York City.

LULU: And as the horticulturalist, Stephanie is the person who cares for these trees. Which means A) her official work uniform is often shorts, sneaks and sunglasses; and B) she gets to look up at the sky through those shades and dream about what other trees she could add to this outdoor museum. And a few years back, Stephanie began wishing on a star that a tree grown from a seed that had been to the moon could become the "crown" jewel of the collection. Crown, because the top of trees are called crowns! Heh!

LULU: Anyway, back in 2022, NASA sent a new round of tree seeds to the moon as part of their Artemis I mission. And when Stephanie heard that you could apply to get one of these space-traveling seeds, she and her team of tree-hugging tree gardeners worked super hard on their application, saying why Madison Square Park, their tree museum that around 60,000 people pass by every day, would be the perfect home for a moon tree. They sent it off ...

STEPHANIE LUCAS: And, you know, we didn't hear anything for two years, so I totally gave up. I mean, I really just thought after that first year there was no way we were ever gonna receive a moon tree. And then I was actually just walking in the park, you know, checking up on some watering, and I get this unlisted number. And I pick up, "This is Stephanie." And it's like, "This is NASA speaking."

LULU: Oh!

STEPHANIE LUCAS: "Are you able to accept your moon tree this week? We've been trying to email you." I'm like, "Of course we're ready to accept the moon tree." And they're like, "Okay, great. You should just check your spam." So sure enough, there were three emails from NASA following up. And later that week a box showed up. And it was just a cardboard box, about three feet tall.

LULU: Yeah?

STEPHANIE LUCAS: And on the outside there's a sticker with a little bumblebee on a rocket.

LULU: She opened up the box.

STEPHANIE LUCAS: And we had our little moon tree in a pot.

LULU: So it arrived as sort of a little sapling?

STEPHANIE LUCAS: Just a little sapling, yeah. And we were so scared that it might get stolen. So NASA actually provides guidelines to kind of cage your tree for the first year, to make sure that it's great at establishing roots and has opportune time to really settle into its new space.

LULU: Not gonna get any stray dog pee pee on this one.

STEPHANIE LUCAS: Exactly.

LULU: And to make this little space traveler feel at home in the park, Stephanie and her team are shining light on other celestial-themed plants hidden in the park.

STEPHANIE LUCAS: They have, you know, spotted leaves that look like galaxies.

LULU: Huh!

STEPHANIE LUCAS: Or the big white flowers that only bloom at night. So that's part of our moon garden.

LULU: A moon garden, which is a magical kind of garden that is best enjoyed at night, full of plants with silvery surfaces that almost glow in the moonlight or flowers that release their scent at night.

LULU: And why would a—why would there be flowers that only open at night?

STEPHANIE LUCAS: It depends on the pollinator. So many plants are pollinated by moths or by beetles that are nocturnal, so they want to put their flowers out when those insects are active.

LULU: Oh!

LULU: Now, alongside this array of intergalactic flowers, there grows one of the rarest plants on earth, a moon tree.

LULU: Can we go just say hi to her?

STEPHANIE LUCAS: Yes.

LULU: All right. Hi, little moon tree. Okay, walking up to the moon tree. Are you gonna let us touch it?

STEPHANIE LUCAS: Yeah, of course.

LULU: [laughs]

LULU: I felt her soft leaves.

LULU: Look at her silky leaves, this sweetgum.

LULU: Wrapped my hand around her trunk, which was just the width of a crayon.

LULU: How wild to think that the little seed that grew you has been to the moon. It's little, but it's got a lot of life ahead.

STEPHANIE LUCAS: Yeah. So this'll be a 35- to 40-foot tall tree. She'll be very spectacular, hopefully around the same size and same shape as our big tree over here, our English elm.

LULU: I look over to that massive elm. Underneath it, a mom and baby are on an orange picnic blanket, lying in its shade, and I think about the stories that might unfold one day under the shade of this being that has been to the moon.

LULU: I bet we're gonna get a proposal. I bet we're gonna get an awesome nap.

STEPHANIE LUCAS: I would take an awesome nap under this tree.

ANA: I think you should get the first one.

LULU: Yeah!

STEPHANIE LUCAS: Nice. [laughs]

LULU: And on Thursday, July 16, there is gonna be a party to celebrate the moon tree in the park with real-life astronomers you can ask your questions to, stomp rockets to set off, solar binoculars through which you can safely peer at the sun—which I didn't even know you could do. And Alan, Alan's gonna be there with some of the other friends from the Terrestrials team. And you can snap photos with them. And there is also going to be some very incredible artwork on display, specifically your moon tree drawings! That's right, many of the drawings that you guys submitted of what you think a moon tree would look like when it grows are going to be on display in New York City, in the park. You can come see them, or draw new ones. There's also gonna be a drawing competition, and so much other family-friendly, celestial-themed stuff.

LULU: Does it cost a ton of money to come?

STEPHANIE LUCAS: No, it's free. A totally free public program.

LULU: And the highlight of the event will be the unveiling of the moon tree with a plaque near it, inscribed with a brand new poem by the New York State Poet Laureate, Kimiko Hahn, which she wrote for the moon tree. In particular, about the astronaut Stu "Smokey" Roosa, who first had the idea to bring seeds to space.

LULU: Okay, so can we—can we hear the poem?

KIMIKO HAHN: The Adventures of the Moon Tree.

LULU: This is the New State Poet Laureate Kimiko Hahn! We got her to read it for us!

KIMIKO HAHN: Stu carried 500 seeds of loblolly pine, sweetgum and sycamore on his Apollo mission around the moon while their siblings stayed home in a nursery. Loblolly pine, sweetgum and sycamore seeds orbited so foresters could see how they'd fare. Their siblings pouted in the nursery. In playgrounds and schoolyards and city parks, orbiting so foresters could see how they'd fare. After Stu returned with the 500 seeds, one moon tree landed in Madison Square Park. After Apollo, after Artemis, she orbited to us.

LULU: Oh! [applauds]

LULU: All right. Well, friends, if you want to go touch the moon—via tree—for absolutely free, just go to New York City, right near the Flatiron Building. Look for Madison Square Park, and head to the northern part of the park, and you will find it. Now let's revisit our episode all about Stu and the very first moon tree mission.

LULU: Three, two, one!

NATALIE MIDDLETON: Imagine that you're teeny, teeny tiny, and you have this hard shell. But inside that shell is everything you need to start growing to 200 feet tall.

LULU: [gasps]

LULU: And you are all set to be an earthling, until somebody launches you, hurls you toward the moon.

NATALIE: And you travel 250,000 miles, the farthest that any living thing has ever been. You see the far side of the moon, where all there is is stars.

LULU: And then you start falling back, back, back towards the Earth at faster speeds where nobody is sure if you'll survive. But when you hit the soil ...

NATALIE: You feel the warm sun, and you unfurl from your shell.

LULU: You have become ...

NATALIE: A moon tree.

LULU: A moon tree?

NATALIE: Yes.

LULU: All right. Now is the part where I make you sing the theme song with me.

LULU: [singing] "Terrestrials. Terrestrials. We are not the worst, we are the ..."

NATALIE: "Bestrials."

LULU: Yes, you got it!

LULU: Terrestrials is a show where we uncover the strangeness waiting right here on planet Earth. I am your host Lulu Miller, joined as always by my Songbud ...

ALAN GOFFINSKI: [singing] I do believe ...

LULU: Alan.

ALAN: [singing] ... we took those trees to the moon!

LULU: And today we are joined by one of our favorite storytellers, one of the people who fact checks our Terrestrials episodes to make sure everything we're saying is true.

LULU: Can you please introduce yourself?

NATALIE: Hello, I'm Natalie Middleton.

LULU: So it's funny that you are the person on our team who kind of certifies truth, because you are bringing us a story that sounds like science fiction, like sci-fi!

NATALIE: Yeah [laughs]

LULU: Where do we start?

NATALIE: This whole story begins all thanks to a firefighter called Stu "Smokey" Roosa.

LULU: Oooh, Smokey's his middle name?

NATALIE: That's his nickname, yeah.

LULU: Or nickname. Smokey. Okay, Smokey the Firefighter.

NATALIE: Originally born in Colorado in 1933. Redhead, freckles, tall, kind of lanky. Prankster. He's whip smart, really good at math. And he absolutely loved trees.

LULU: And after high school, he got a job with the forest service trying to fight this fungus called blister rust.

NATALIE: Which is a fungus that is really hard for trees to survive.

LULU: So you're saying he loved them so much his actual job was to protect them from getting sick?

NATALIE: Yeah. And so every summer after that, he would go and fight fires. What he became is called a "smoke jumper."

LULU: A smoke jumper? That sounds a little scary.

NATALIE: It's pretty dangerous. So they're jumping out of planes with a parachute, basically into the fire.

LULU: Wow! Are they wearing, like, fireman gear? Like the jacket and ...?

NATALIE: It's actually kind of similar to, like, an astronaut suit.

LULU: Hmm!

LULU: And at some point as he's floating through space, he wonders what it would be like to float through space. Higher space. Outer space. So first, he learns how to fly a plane.

NATALIE: Yes.

LULU: Then he trains and becomes an astronaut.

NATALIE: He just kind of went up higher in the sky. [laughs]

LULU: [laughs]

LULU: And one day, NASA tells him he's going to the moon.

NATALIE: Apollo 14.

LULU: And his job?

NATALIE: He's going to be the pilot.

LULU: Whoa! He's flying the spaceship?

NATALIE: Yes.

LULU: Wow! Go Smokey!

NATALIE: It's a big job.

LULU: So the year is 1971. The spacecraft is all loaded up with gear and fuel. And each astronaut gets to bring with them one little bag.

NATALIE: It's not big. It's, like, almost like a pocket size.

LULU: It's made of a special type of glass.

NATALIE: That won't melt until it's hotter than over a thousand degrees Fahrenheit.

LULU: Whoa, that's like a furnace!

NATALIE: Very fireproof. 

LULU: And what can they put in there? Is it like their license and toothbrush?

NATALIE: Yeah, so astronauts actually just get to bring whatever is meaningful to them.

LULU: Aww! What would you bring?

NATALIE: Oh! [laughs] So I have a daughter that's two. She drew a train. And yeah, I would probably bring that.

LULU: Hmm. What did Smokey bring?

NATALIE: So out of everything that he could have thought to take on Earth, he chose to take tree seeds.

LULU: Back to his love of trees. He can't shake it!

NATALIE: [laughs] Yeah.

LULU: He brought a big handful of five types of seeds.

NATALIE: Sweetgum.

LULU: Leafy trees from the east coast of the US.

NATALIE: Loblolly pine. They're from the South.

LULU: Loblolly, loblolly, loblolly. That's fun to say.

NATALIE: We have the redwood tree.

LULU: Oh! Those big, giant from the West Coast that are too big to even hug!

NATALIE: Then we have the sycamore.

LULU: Super tall, leafy ones. Lots of them in the middle of the country.

NATALIE: The last one is the Douglas fir.

LULU: Hmm! It's like a Christmas tree that are often Douglas firs, right?

NATALIE: Yes. They chose trees that could be grown all across the whole entire country.

LULU: Yeah.

NATALIE: And they put them in this aluminum metal canister. Very small, it fits in the palm of your hand. So 500 of these seeds fit in the palm of Smokey's hand.

LULU: Wow!

LULU: And so the day of the launch, he puts this canister of seeds in his little white fireproof bag, waves to the masses, and steps onto the spacecraft.

NATALIE: From a scientific standpoint, people just didn't know what would happen to a plant or a seed if you took it up into deep space.

LULU: Had no one ever taken one up before?

NATALIE: No. So this was the first time.

LULU: Huh!

LULU: And he had a scientific question.

NATALIE: What would happen if we brought another living thing up into space with us that's different than us?

LULU: Would it survive?

NATALIE: Yeah, would it survive? Would it grow differently? Would it look like a totally different kind of tree?

LULU: Because as Natalie explained, they knew that space affected humans.

NATALIE: When you're out in space, you're exposed to stronger radiation from the sun and galactic cosmic rays.

LULU: And this radiation can wiggle its way into your DNA, the blueprint that tells your body how to grow and potentially warp things. Plus, the lowered gravity can weaken your bones and muscles. And oddly, because of something about how time works in space, you age just a tiny bit slower!

ALAN: [singing] Which I still don't really understand but I gotta keep moving on with the story.

LULU: And so Smokey—and some of his fellow tree lovers at the forest service—wondered would space have an effect on the cells and DNA inside trees?

LULU: Did he have any hypotheses on how it—space travel might affect growth of these trees?

NATALIE: So I looked. There's nothing that indicates what he thought, except that he thought it was a cool idea. [laughs]

LULU: Okay. Well, lucky for you, Natalie, I put the question to a bunch of children.

NATALIE: Oh! [laughs]

LULU: And would you like to hear some of their answers?

NATALIE: Yes, I would!

[ARCHIVE CLIP, child: Maybe it would have to grow not with any water.]

[ARCHIVE CLIP, child: It would probably have different needs. Instead of, like, water, maybe something else, different chemicals helping it grow.]

[ARCHIVE CLIP, child: Maybe it would have to be growing on no gravity?]

[ARCHIVE CLIP, Lulu: So how would that make the tree look different?]

[ARCHIVE CLIP, child: So the branches would arch, and then turn into spirals.]

[ARCHIVE CLIP, child: Trying to go upwards a little higher because of just, like, the generally lower gravity on the moon.]

[ARCHIVE CLIP, child: And there's also gonna be berries. Golden berries, a brined berry.]

[ARCHIVE CLIP, child: Maybe, like, blue leaves?]

[ARCHIVE CLIP, child: Um, a white trunk.]

[ARCHIVE CLIP, Lulu: Ooh!]

[ARCHIVE CLIP, child:  And it looks like a palm tree, but ...]

[ARCHIVE CLIP, Lulu: It looks like a what tree?]

[ARCHIVE CLIP, child: A palm tree.]

[ARCHIVE CLIP, Lulu: Oh, it's like a palm tree.]

[ARCHIVE CLIP, child: But, like, white and gray. But inside of the coconuts is a piece from the moon.]

[ARCHIVE CLIP, Lulu: Ooh! Is it hard or soft inside?]

[ARCHIVE CLIP, child: Tastes like yogurt.]

[ARCHIVE CLIP, child: And probably have a little metal in it.]

[ARCHIVE CLIP, child: Then at the end of them, they were like a little moon-like half crescents and full crescents and stuff like that.]

[ARCHIVE CLIP, child: And if you touch one, you'll start to feel, like, tingling in your hand. And if you give one to your animal, your animal will get this little moon shape on its forehead and then they'll be able to, like, fly and stuff.]

NATALIE: Oh my God, Lulu! These are so ...

LULU: I don't—I just put the question out. Isn't this great?

NATALIE: It just catches imagination, doesn't it?

LULU: Mm-hmm.

NATALIE: It's so fitting, Lulu, because it's really thanks to a third grader that we even know about this story.

LULU: Wait, what?

NATALIE: Yeah.

LULU: That story—plus blast off—after this short break.

LULU: Ten.

NATALIE: Nine.

LULU: Eight.

NATALIE: Seven.

LULU: Six.

NATALIE: Five four three two one ...

LULU: Thwoom!

NATALIE: Blast off.

LULU: Goodbye Smokey! Goodbye—what are the other names of the other astronauts?

NATALIE: Edgar Mitchell and Alan Shepard.

LULU: Goodbye, Ed! Goodbye, Alan! Goodbye fireproof bag full of seeds! Whee!

LULU: The fuel ignites. And on the outside the spacecraft looks pretty slow. But on the inside, everything is rattling. The metal rivets are groaning, and the seeds in the canister are bumping into each other. There's all this pressure from gravity trying to pull the spacecraft down. And then in one instant, it severs ties from Earth.

NATALIE: And suddenly, the seeds and the astronauts are floating in zero gee.

LULU: And Smokey aligns his measurements and lurches the spacecraft toward the moon!

[ARCHIVE CLIP, NASA: Stuart, how is your peanut butter?]

[ARCHIVE CLIP, Stuart Roosa: Not enjoying any peanut butter.]

LULU: This is audio from the actual space flight!

[ARCHIVE CLIP, NASA: Incredible.]

[ARCHIVE CLIP, Stuart Roosa: It's really a wild place up here.]

LULU: For four days they soar through space, as that little moon in the sky grows bigger and bigger and bigger.

[ARCHIVE CLIP, Stuart Roosa: It seems so close. It's like you can just reach out and touch it.]

LULU: Until they are right next to it.

[ARCHIVE CLIP, NASA: Stu, we just got word that your family is listening to you, and they're outside looking up at that great big moon. I'm sure we'd all like to be up there with you. Over.]

LULU: And then Stu, aka Smokey ...

[ARCHIVE CLIP, Stuart Roosa: Yeah, I wish you could be.]

LULU: ... releases Alan and Ed from the spacecraft to go land on the moon.

[ARCHIVE CLIP, Alan Shepard: Nothing like being up to your armpits in lunar dust.]

LULU: They get to go walk on the moon?

NATALIE: Yes.

LULU: Lucky Alan. Lucky Ed.

NATALIE: [laughs] Yeah.

LULU: And not only did they get to frolic around in moon dust, Alan brought a makeshift golf club and golf balls to hit.

NATALIE: Because of the gravity, you barely have to tap it and it just flies.

[ARCHIVE CLIP, Alan Shepard: Miles and miles and miles.]

LULU: I'm just picturing, like, it's like, [sings] Alan and Ed, playing on the moon. Bouncing, feeling, doing what they do. And Smokey doesn't get to go.

NATALIE: [laughs] Yeah. Well, that's what I thought.

LULU: Yeah.

NATALIE: But actually, for every moon mission where people land on the moon, there's one astronaut that stays in orbit around the moon. And it's a really important job, because that's everybody's ...

LULU: It's important, but it sounds less fun!

NATALIE: Okay, but you'll see why I say that. So the command module, so that's what Smokey is in ...

[ARCHIVE CLIP, NASA: Stu Roosa aboard Kitty Hawk.]

LULU: Okay.

NATALIE: He's gonna continue to orbit around.

[ARCHIVE CLIP, NASA: Eighth revolution of the moon.]

NATALIE: He's gonna take pictures. He's gonna do all these science experiments while he's ...

[ARCHIVE CLIP, NASA: Fifteenth ...]

[ARCHIVE CLIP, NASA: Nineteenth ...]

[ARCHIVE CLIP, NASA: Twentieth revolution of the moon.]

NATALIE: ... orbiting and orbiting and orbiting.

[ARCHIVE CLIP, NASA: The twenty-second lunar revolution. Twenty-three. Roosa's still apparently asleep.]

NATALIE: I think he orbits ...

[ARCHIVE CLIP, NASA: Thirty-second revolution.]

[ARCHIVE CLIP, NASA: Thirty-fourth.]

NATALIE: ... thirty-four times.

LULU: [gasps] The moon?

NATALIE: The moon.

LULU: Wow!

NATALIE: And what happens when you're orbiting the moon is that you end up going into the moon's shadow.

[ARCHIVE CLIP, NASA: Now passing over the backside of the moon.]

NATALIE: Which is called the "far side" of the moon. And when you do that, everything gets really dark. You can't see the sun. It's cold, the temperature drops, things get, like, really clammy. And then you also lose contact with everyone on Earth.

[ARCHIVE CLIP, NASA: We have had loss of signal with the command module, Kitty Hawk.]

NATALIE: And everyone on the moon. Literally it's Stu "Smokey" Roosa and these seeds in his pocket ...

LULU: Are the only living things in that corner of the world.

NATALIE: Yeah.

LULU: Okay Natalie, you're not selling me. I'm ...

NATALIE: Well, let me—let me ...

LULU: You're just like, "You are the most alone person of the entire living human race."

NATALIE: Yeah.

LULU: You're cold. But get this! You're also clammy and it's pitch dark.

NATALIE: [laughs] Okay, so ...

LULU: And the other guys are, like, having fun bouncing and playing golf on the moon.

NATALIE: So yes, I left out the best part. So when you're going around, what happens is you suddenly see just this sheet of stars that just goes on forever and ever and ever.

LULU: Hmm!

NATALIE: The astronauts that have experienced that have just, like, plunged into that side of space that no one ever gets to see.

LULU: But he can't admire the infinite void forever, because he's starting to run out of gas. So he brushes by the moon, picks up Alan and Ed ...

[thanks, bro!] 

LULU: ... lurches the spacecraft back toward Earth.

[ARCHIVE CLIP, NASA: We'll see you on the other side. Over.]

LULU: And start divebombing toward it, traveling at over 16,000 miles per hour, until ...

[boom!]

NATALIE: They splash down in the Pacific Ocean under these three huge orange and white parachutes.

LULU: Huh!

NATALIE: So the seeds made it back to Earth. They traveled so far. And then during the decontamination process, the cleaning process, there was an extreme change in pressure and the bag of seeds explodes.

LULU: [gasps] Oh, no!

NATALIE: So the seeds just exploded all over the place, and everybody thought that they had killed them.

LULU: But the show must go on, the science must go on. So they sent them to forest service greenhouses, where they planted all the seeds in soil. The sycamore seeds, which looked like tiny green pistachio nuts, and the Douglas firs, which looked like scales plucked from a pinecone, and the sweetgums, and loblollly pines and the mighty redwood, which all begins in a tiny package that looks a little like a flattened corn kernel. And they watered them. And let the sun shine its warm rays. And then they waited. And they waited. And ...

NATALIE: Almost all of them came up.

LULU: [gasps] Whoa! And so that's how many little saplings are growing?

NATALIE: The estimate is 420 to 450.

LULU: Of the 500?

NATALIE: Yeah.

LULU: And are they seeing any difference in that growth? I think about our kids, and all the hypotheses and the spiral arms and the low gravity and the crescents. Like, was there—were they seeing any difference at first?

NATALIE: Actually, there was no difference.

LULU: At first. But trees, famously long living, take a long time to grow—sometimes hundreds of years to reach their full height. So to continue the experiment, NASA planted the baby moon trees all over the country.

NATALIE: There was a moon tree planted at the White House.

LULU: Huh!

LULU: At state capitols.

NATALIE: At NASA centers.

LULU: At a governor's mansion, a military fort.

NATALIE: But then they also got planted in front of a junior high, at a Girl Scout camp.

LULU: Huh! 

NATALIE: Right outside of a cemetery. So just all of these places all over with regular people got these moon trees.

LULU: Yeah. Did anyone, like, get one in their yard?

NATALIE: Yes, people actually did.

LULU: Really? No! Just like Diane in Nebraska or whatever?

NATALIE: Yes. There are moon trees at private residences.

LULU: [laughs] How cool!

NATALIE: Yeah. The funny thing is, though, so when they would do these ceremonies, sometimes they would put a plaque in, but other times they would just have the ceremony and then go along their merry way. And over time, people started to forget that these were moon trees.

LULU: Time presses on. The Berlin Wall falls and the Mount St. Helen's volcano erupts and the trees keep growing, holding their secret inside. And Smokey Roosa dies, and you are born. And the moon keeps shining, and the experiment is mostly forgotten. Until one day, a little girl in Indiana, notices something funny at her Girl Scout camp—a sycamore tree with a little plaque.

NATALIE: Yeah, it just says, like, "Moon Tree, 1976."

LULU: Huh!

NATALIE: Nobody remembers even at the Girl Scout camp, like, what this was.

LULU: Wow!

LULU: So she tells her third grade class teacher, Ms. Goebel, about it.

NATALIE: Ms. Goebel emails NASA.

LULU: [laughs] Just says, "Hey, NASA! Dear NASA. Question."

NATALIE: Yes. [laughs] So the email finds its way to Dr. Dave Williams, who is a planetary scientist at NASA. And he doesn't know.

LULU: Oh!

NATALIE: And he told me that nobody remembered.

LULU: Wow!

NATALIE: And that there was no official record of where the trees had been planted. So Dave decides NASA should go on a recovery mission of sorts, and he starts a website that basically says, "If you have a moon tree or you know of a moon tree, let me know."

LULU: Wow!

NATALIE: And he started getting these emails from people who were like, "Hey, there's a moon tree in my plaza in my town. There's a moon tree in front of the hospital where I went."

LULU: Huh!

NATALIE: Slowly, he's collected locations of these moon trees as people have kind of rediscovered them in their own backyards.

LULU: And made kind of like a map?

NATALIE: He didn't make a map. I made a map.

LULU: [gasps] You made a map?

NATALIE: Yeah, it's pretty cool.

LULU: Wait, really?

NATALIE: Yeah. [laughs]

LULU: Cool!

NATALIE: In my map, you can spin the Earth, and then you can, like, click on your—to see what moon tree is close to you.

LULU: And we have this linked this on our website and right here in the episode description. Just click on "Natalie's moon tree map."***[https://arcg.is/1THGOi3]

NATALIE: Here we go.

LULU: And Natalie ...

[ARCHIVE CLIP, GPS: For about 63 miles, continue straight.

[ARCHIVE CLIP, Natalie: We're gonna go find our moon tree now.]

LULU: ... realized there was one not too far from her in California, in a town by the sea called ...

NATALIE: San Luis Obispo.

LULU: Cool little surfing town.

[ARCHIVE CLIP, Natalie Middleton: I'm walking down some stairs and I see a little creek.]

NATALIE: And it took me a while to find it.

[ARCHIVE CLIP, Natalie Middleton: Holy cow. I found it!]

NATALIE: The plaque was very small. Like, I can see how people kind of just walk right by.]

[ARCHIVE CLIP, Natalie Middleton: And I'm gonna try to hug it, see if I can get my hands around it. Oh! Oh my gosh, not even—not even halfway around. [laughs] And it smells so good!]

NATALIE: And when I saw it, it was just—I actually got kind of emotional.

LULU: Huh.

NATALIE: Like, I went up to its trunk and I, like, touched its bark and I started to cry. [laughs]

LULU: Why?

NATALIE: Space exploration is one of those things where not that many people get to experience it, and yet it's something that humans have wondered about for millennia, ever since we could wonder we were looking at the stars and the moon. So to be able to touch a living thing that has actually traveled all the way to the moon and back and survived? It's a deep thing.

LULU: So for you the thing is like—is it almost like access? It's like almost getting to touch the moon?

NATALIE: It's poignant. I don't know—I don't know more of a kiddie word for that. It's like ...

LULU: Well, how would you describe poignant for someone who doesn't know what it means?

NATALIE: I would say it's like a joyful kind of ache. We usually tend to think of trees as rooted, and so to realize that these are travelers and that they've traveled so much farther than I will ever travel.

LULU: Yeah.

NATALIE: And then I looked up, and it just—it has—redwood trees have these huge kind of feathered branches that are just so beautiful. And there were, like, little threads of spider silk that were, like, catching the sun, little rainbows of spider silk. There was like a squirrel jumping around up there. There were birds. I kind of went and sat on a bench nearby, and there was this whole construction crew that was on lunch break, and they all went and sat under the leaves of this moon tree. And I'm pretty sure they had no idea that it had been to the moon.

[ALAN: [singing] I want to know the truth tangled in your roots, the things you've been through that make you you. I want to know the truth tangled in your roots. Every leaf, every tree holds a history tangled in the roots. Did you float through the shadows alone, surrounded by a silence that no one else knows? Tangled in the roots. Were you lost in the ocean of stars where it all fades to dark and the air goes cold? Tangled in the roots. Did you go to the dark side of the moon? Would you talk about the feeling, talk about the view? Tangled in the roots. Are you back down on the ground now, just waiting around now, humming a tune, waiting to bloom? Tangled in the roots, the things you been through that make you you. I want to know the truth tangled in your roots. Every leaf, every tree holds a history. Tangled in the roots. Spinning towards the stars. Do your branches spin towards the stars? Spirals of leaves defy gravity. Spinning towards the stars. Yeah, this journey we're traveling on, the spindle of secrets, sprouts from a seed. I want to know the truth tangled in your roots, the things you've been through that make you you. I want to know the truth tangled in your roots. Every leaf, every tree holds a history tangled in the roots.]

LULU: Alan Goffinski! He is a good tree! He's a great one. There is nothing else cool about to happen. What's that?

BADGER: Excuse me, I have a question.

BADGER: Me too.

BADGER: Me three.

BADGER: Me four.

LULU: The badgers! They're listeners with badgering questions for the expert. Are you ready?

NATALIE: Yes.

ALEX WINTER: Hi. I'm Alex Winter. Also known as Bill from Bill and Ted's Excellent Adventure.

LULU: [gasps] Most triumphant.

ALEX WINTER: My question is: is it true that time moves differently in space? Like, if I had a twin and he went to space, would we be different ages?

NATALIE: Oh yeah. Earth ages faster.

LULU: Oh, so if you went to space, you'd be younger?

NATALIE: So Scott Kelly and his brother Mark Kelly are identical twin astronauts that did a science experiment. Basically, Scott went up and stayed for almost a year in space.

LULU: Whoa!

NATALIE: And because of something known as the "twin paradox," time passed more slowly for Scott up in space than for his brother Mark here on Earth. And what that means is that Scott returned to Earth younger ...

LULU: What?

NATALIE: ... than his brother Mark.

LULU: How much younger?

NATALIE: 8.6 milliseconds younger.

LULU: [sings] I don't understand, but I like it!

TOMMY: Hi, I'm Tommy, I'm 11 years old, and my question is, would NASA ever plant seeds in space?

NATALIE: They did.

LULU: They did?

NATALIE: Uh-huh. So they were called, like, the veggie experiments.

LULU: Okay.

NATALIE: In recent years, astronauts took vegetable seeds up to the International Space Station.

LULU: Whoa!

NATALIE: To see if they could grow them in hopes of, like, if and when we kind of push our way out to Mars, the astronauts are gonna have to grow their food. Like, they're not gonna be able to pack all the food they need.

LULU: Oh, right! Of course.

NATALIE: So Scott Kelly, the twin, part of what he was doing in space for that whole year was trying to grow plants.

LULU: Oh my gosh!

NATALIE: Yeah. But it's hard, because watering them—so when you water plants in space, the water beads up in microgravity, and it makes it really hard for it to reach the roots.

LULU: Hmm.

NATALIE: And so you have to sort of, like, force it into the soil. And NASA also was making him wear gloves so that he wouldn't accidentally get a mold or something from the soil. But the thing was is that with the gloves on, he couldn't tell if the flowers were getting enough water or too much water.

LULU: Oh, like he couldn't feel the soil, kind of?

NATALIE: Yeah. So finally, he ...

LULU: He broke the rules? Ripped off the gloves?

NATALIE: He took his gloves off! [laughs]

LULU: So he could feel the soil.

NATALIE: Yeah. And a little while later—check this out.

LULU: Oh my gosh, you are showing me a picture of these gorgeous orange flowers. Are these—are these—did these bloom out in space?

NATALIE: Yeah. These are called zinnias, and they bloomed in space.

LULU: [singing] Twinkle twinkle little zinnia.

THEO: Hi, my name is Theo and I'm nine years old. Does NASA have any plans to keep studying moon trees?

NATALIE: So the Artemis mission recently took seeds again to the moon.

LULU: Oh! So moon trees, part two!

NATALIE: Yeah, moon trees, part two.

LULU: Okay, and I have one last question. By this point, have they located all of Smokey's original, you know, 450 moon trees?

NATALIE: No, there's just over a hundred that they know the locations of now.

LULU: Oh. So most of them are still missing?

NATALIE: Most of them are still out there growing. And nobody knows that they went to the moon.

LULU: But you can look for them, look for their little plaques. And if you find one, drop an email to Natalie [at] nataliemiddleton [dot] org so that she can add its location to her map and more people can also touch the moon—via tree.

LULU: Natalie, I love knowing that this whole forgotten treasure map of trees with this lunar secret inside was unearthed by a third grader?

NATALIE: Thanks to a third grader.

LULU: All right, that is where we’re gonna leave it. Don't forget what secrets, what otherworldly truths, you might unearth for all of us, if you just stay curious. Ask questions. Don't pretend you know the answers, just say simply, what is this? What is that? What are you?

LULU: Terrestrials was created by me, Lulu Miller, with WNYC Studios. This episode was produced by the very "lune-y—" like lunar?—Tanya Chawla, with sound design "tree-ats—" spelled T-R-E-E—by Joe Plourde. Our executive producer is Sarah Sandbach. Our team also includes Alan Goffinski, Ana González and Mira Burt-Wintonick. Fact-checking by Diane Kelly who is always "rooting" for the truth. Special thanks to Sumanth Prabhaker, who first nurtured this story at Orion Magazine. You can check out Natalie's gorgeous essays about moon trees and space zinnias over at orionmagazine.org. Thanks also to NASA scientist Dr. Dave Williams who did so much work to uncover this map of moon trees. He has recently retired. Thanks also to NASA scientist Dr. Marie Henderson, third-grade teacher Joan Goebel and former third-grade student Tre Corely.

LULU: Support for Terrestrials is provided by the Simons Foundation, the Arthur Vining Davis Foundations and the Templeton Foundation—thank you!

LULU: And one more time, you can find all the links we talked about today: How to find a moon tree near you, and how to submit a location of a moon tree if you find one. All that on our website, TerrestrialsPodcast.org. Just search for the episode "The Travelers: How Moon Trees Hide Among Us." Oh, and finally, if you visit a moon tree, snap a picture with it and tag us on social media @terrestrialspodcast. We'd love to see you!

LULU: All right, that'll do it for today. See you in a couple spins of this dirty old planet of ours.

See you in a couple spins of this dirty old planet of ours. Bye!

 

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